Znternal-combtjstioit rotary



C. O. FARNHAM.

INTERNAL COMBUSTION ROTARY ENGINE.

APPLICATION HLEDINOV. 23, 1918.

1,308,896. Patented July 8, 1919.

7 SHEETSSHEET 1.

Jwarziaz C. 0. FARNHAM.

INTERNAL COMBUSTION ROTARY ENGINE.

APPLICATION FILED NOV.23. 1918.

Patented July 8, 1919.

7 SHEETS-SHEET 2.

r/m aiar C. 0: FARNHAM.

INTERNAL COMBUSTION ROTARY ENGINE.

APPLICATION FILED NOV. 23. 1918.

1,308,896, I Patented J uly 8, 1919.

7 SHEETS-SHEET 3.

C. 0. FARNHAM.

INTERNAL COMBUSTION ROTARY ENGZNE.

' 1 ION FILED NOV 23.1918

APPL CAT 1 ,308,896. Patented July 8', 1919.

TSHEETS-SHEET 4.

C. 0. FARNHAM. INTERNAL COMBUSTION ROTARY ENGINE.

APPLICATION FILED NOV. 23,19I8.

Patented July 8, 1919.

ISHLETS-SHEET 5.

w 1 5V q u 1 6 m/ r 1 6 7/ w i, a 7 v a C. 0, FARNHAM.

INTERNAL comsusnow ROTARY ENGINE.

APFLICATIONFILED NOV. 23. 1918.

Patented July 8, 1919.

7SHhETSSHEET 6.

C. O. FARNHAM.

INTERNAL COMBUSTION ROTARY ENGINE.

APPLICATION FILED NOV. 23. I918.

Patented July 8, 1919.

7SHEETSSHEET 7.

can't. o.. ran.1- rnAM,-or PARIS, ILLINOIS, '1-

INTERNAL-COMBUSTION ROTARY ENGINE.

i,sos,seo.-

To all whom; it may concern Be it known that I, CARL O. FARNHAM, a citizen of" the' Unit'ed States,v residing at Paris, in the county ofE'dgarand'State of Illinois, have inventedf'certain new and useful Improvements inInternal-Combustion Rotary Engines, of which the following is ton chamber, the explos ve mixture being long as the engine'is in operation.

a'spe'cification. y I

My. invention relates to internal combustion rotary engine in whichlafseriesof.

pistons arearranged to travel continuously. in a circular path throu-ghgan annu1ar'p1s-' taken inbetween two pistons at one point in their travel, compressed by relative .movenient of such pistons at a-laterpoint and the compressed-charge then ignited, the

expansion of the burning'gases acting on the pistons to separate them' 'and this relative movement being caused-to impart a ro i.

tative movement to the power shaft, burning gases then exha by a r613. I

tive movement of the pistons toward each other, after'wh ich the two pistons separate to-take in a fresh charge of explosive mixture and the operations are repeated so This cycle of operations corresponds substantially to the four-stroke cycle or Otto cycle of widely used reciprocating gasolene en gines. The object of my invention is to provide a motor of this type which through novel and simple mechanism for trans initting the stress uponthe pistons developed by the combustion of the gases to the power shaft shall' be. eificient and desirable for thepurposes in View. Furtherobjects,

I ancillary and incidental to the main pur-' and construction'ofthe difierent parts. of

pose of my ,invention', .relate to a novel,

method of scavenging the exhaust chamber of burnt gasesby air, and the arrangement the engine to'accomplish the functions for which they are designed. The essential elements of' my invention are more particu-klarly pointedout-in the'appended claims, it being understood, however, that variationsin the form and proportions of the parts of v scopeof the claims.

the particular structures hereinafter de scribed may be; made without departing from the substance of m'y'invention or the In Figures 1 to 8 of the'drawings forming p rt ofthis application Ihave illustrated Specification of Letters Patent.

anysuitable manner, as'by the'integral sup- Patented JuIyS, 1919.

Application fl1edNovember 23,-1918.. Serial No. 263,800:

an engine exemplifying one form of invinvention, and in Figs. 9 to 16 I have illus trated a different and preferred form having a modified arrangement of cooperating members and including means for scavenging the explosion chambers of burned gases by a vchargeof air at the end of each" exhaustvention; Fig. 2 is asimilar view, butwith the front casing plate removed showing the pistons exposed to view; Fig. 3 is a vertical ,diametrical section, looking in the di rection of thearrows 33 of Fig. 2; Figs.

4, 5, 6 and 7 are fragmentary views illus- J s's i movement of a' pair of cooperating-pistons. I. Ofthe drawings Fig.1 is a front elevation of the first-mentioned form of my intrating successive positions of a pair of 00- v operatmg pistons in their travel through the annular piston "chamber; Fig. 8 is a transverse section on the line 8-8 of Fig. 2';

Fig.9 isa front view of. the preferred and modified form' of -my invention with the. front ,casin plate removed; Fig. 10 is a V diametrical' orizontal section of the same,'

looking downward; Fig. 11 is alinear' eX- tension of the pistons 'shownat the right-' hand side of Fig. 9, on the' line 1O 1O of Fig. 9 and viewedin the direction of; the arrows; Figs. 12 and 13 are views illustrating I successive positions of-the toggles .and istons; and'Figs. 14, 15 and 16 are sections on the lines 14.-14, 15 -15, audit-16 of'- Fig. 9, showing *the arrangement f oer.

' The same-reference 'charactersiiidicate-the I? Describing first theembodiment ogf-myin- I venti'on' illustrated in Figs l to 8, .1'nclus1ve,l'f-

sameparts in all the figuresiofthe drawing.

the annular pistonf chamber in "which the plllatespa: front p ate 1 and a W in two casing rear plate 2,

" pistons travel 'may convenientl "be formed 5 ch are securedtogether by I bolts passing through flanges extending around their periphery and are supported in porting arms 3. jAs'showmthe rear casing plate consists of a rimportion which is semiflflj circular in cr0ss-sect1on ,=*afflat central porjfi ceive the power shaft, and radial 'stre'ngthen" v i'ng flanges. The front 'casing plate consists of a similar'rim portion and is formed'with'" aninwardly extending bracket-g1"? the v innerjend' of which is mounted 'aneccentric "to, the flangesof the casing members 1 and 2 pin 22, the'purpose of which will be later explained I provide a water jacket alon that portion of the piston chamber 1n who the burning of the gases takes place and the heated gases exhaust, by means of arcuate plates 4 and 5 which are secured respectively and to arcuate walls 6 and 7 extending outwardly from the inner side of such casing members.

Arrangedwithin the annular piston chamber area plurality of pistons, in the present instance eight in number, four of which,

-.-marked A, A A and A are carried respectively by arms 14 and 15secured to a hub 16 which is rotatahly mounted onthe motor shaft; and the other two pistons,

marked B and B are respectively carried by ;arms 17 and 18 fixed to a hub19 which. is

also rotatably mounted coaxially' of the motor shaft, the hub 16 being shouldered to provide a bearing for the hub 19 so that the two hubs are rotatably nested together as illustrated- A cap 20 secured to the motor shaft is provided to prevent disengagement of the parts.

Asshown (see Figs. 3 and 8), the casing plates 1 and 2 do not meet around the inner side of the annular piston chamber but are formed with opposing flat faces between i which the arms carrying the pistons rotate.

1 Thearms are formed to. make a sliding gastight-engagement with these faces, and are provided with over-lappin arcu'ate 'exten sions so arranged as to sea every alternate space between the pistons. In the present instance, as illustrated, the extension 11 of the arm 11 cooperates with the extension 14:

of thearm 1 1 to seal the space between the pistons A and C, and like extensions 8 and 17", 9* and 15 and 10 and 18, seal the out idly.

spaces between the pairs of istons A and B, A and C and A and respectively; The intervening spaces are open to atmosphere and 1e arm 11 of the frame carrying the pistons A, A A and A isiconnected by a toggle 19-20 with the arms 18 carrying (together with arm 17 the pistons B and B, and the knee of the toggle is pivotally connected by a link 21 with the eccentric pin 22 mounted in the bracket 1 heretofore mentioned. A similar toggle 2%24 connects the arms 10 and 15, and a pivoted link 25, similar to the link 21, connects the knee of this toggle with the eccentric pin 22. Since the arms 9, 10 and 11 are parts of one rigid frame connected to the motor shaft, and the arms 17 and 18 are rigidly connected and rotatable with respect to such shaft, it is obvious that as the motor shaft revolves the piston B will, through the action of the toggle 19-20, and'the link 21, successively shift from a; position of proximity to the piston ri -with which it 00- pprmit the air to breathe in and.

operateswhen the toggle members are inv line (nearly the position-shown in Fig. to a position where they are remote, th'eeccentric pin and toggle joint being then in line with the axis of the motor shaft, as shown in Fig. 5, and will again approach a position of proximity when the toggle joint passes its dead center, and then separate to .1:emote position as the toggle joint and eccentrio pin and motor shaft come into line on the other side of the motor shaft, as shown in Fig. 7. It is further obvious that the cooperating pistons B and A will describe exactly similar movements, and that by the action of the toggle 23-24 and link 25 the two pairs of'cooperating pistonsA C and A C will pass through thesame cycle of movements. It Will therefore suflice to explain the action of the pair of pistons A B shown in their successive positions in Figs.

The inlet port 26, it should be first explained, consists of a series of arcuate openings communicating with a box 27 formed on the side of the casing plate 1, which box communicates through an inlet pipe 28 with means for supplying a suitable combustible vapor, such as a carburetor of any suitable or known construction, not necessary to illustrate. Preferably a check valve 28 of large capacity and light tension is arranged in the fuel passage adjacent the inlet port. The exorts are indicateddia grammatically by otted lines marked In:

let and Exhaust In Fig. .4 the piston A? no has just closed the. exhaust port and the pistons A, B are traveling in a counter-clock-' wise direction toward the inlet port, and the H toggles 1 920 having just passed its straight or extended position the eccentric connection is drawing the arms 11' and 18 together, which has the efit'ect of-separating the pistons,in.other words of causing the piston B to speedup and draw away from the piston A ,until the parts assume-the position shown-in Fig. 5. During the early part of this movement of the pistons the working chamber between the pistons is exhausted,

and the inlet port is then uncovered by the piston B when the vacuum is relieved by 125. a sudden inflow of explosive vapor. The taking in of fuel then continues until the pistons become separated to their greatest extent, at which point the inlet port is closed by the piston A. As the toggle-joint now r sion tends to separate the pistons and, in effect, the toggle. members 19 and are pressed together with equal force, resulting ing the toggle joint and separating the pisthe position shown in Fig. 4, completing the in a thrust on the knee of the toggle in a direction radial of the motor shaft, Since the link'21 which sustains the pull of this thrust is connected eccentrically to the pin 21, the knee of the toggle is forced outwardly and to the right (as Fig. 6 is viewed,) bendtons and carrying both pistons around in a counter-clockwise direction to the pesition shown in Fig. 7 The exhaust port is now uncovered by the piston 13*, and the exhausting of burned gases continues while the toggle straightens and the pistons approach each other and until such port is closed by the piston A just before the pistons reach cycle of operations.

It is obvious that the pistons on opposite sides of each of the four pistons A, A A and A will approach any given one of those 1 pistons twice at diametrically opposite positions in the course of a single revolution of the motor shaft, and spread apart twice at. opposite points approximately 90 distaiit from the first mentioned positions. These" four pistons A, A A and A being connected' together and to the motor shaft (and the fly wheel, if one is used) rotate at a substantially uniform speed, while the other four' pistons B, B C and C have a variable speed and accelerateand lag to describe the 4 vention a) ove described the spaces in admovements above explained.

In the articular embodiment of my invance of the four constant-speed istons, A, A A and A are sealed and fl inction as working chambers, and the spaces to the rear are open to atmosphere and idle. The spaces to the rear of these constant-speed pistons may be employed as working chambers, however, and in the preferred form of my inven- 7' tion illustrated in Figs. g t o 16, I havefshown such an arrangement. I

.The front plate 31 of the preferred form of my invention now'to be described consists of a peripheral portion 31*, approximately though not completely, semi-circular in cross-section and a central bowl-shaped portion' 31 on which is formed a boss 31 within which is secured an eccentric pin 32, the inner end of this pin being integral with a block 33 bored to form a journal bearing for the end of the motor shaft 34,-see Fig. 10. The rear casing plate 52 is formed with a peripheral portion 5-3 forming the rear portion of the piston chamber and a central back wall 54 integral with the hub 55, which latter provides a bearing for the motor shaft.

As shown the water jacket extends entirely around the outside of the iston chamber, and is formed by front an rear plates 56 and 57 bolted into the casing plates 31' and 52.

Rig-idly secured to'the motor shaft is the *hub 34 of a four-armed frame consisting of the arms 35, 36, 37 and 38, which arms are integral with a fiat ring 39 to which are sewhich are secured the pistons F and F The rings 39, 42 and 45 are disposed between opposite fiat faces of portions of the casing plates 31' and 5-2 adjacent and inside the peripheral portions 3-1 and 53 of such plates, and the outer edges of such rings are curved to conform to the shape of the pistons and make agas-tight piston cl amber. The arms 38 and41 are connected by a toggle consisting of members 46 and 47 the knee of the toggle being connected by a pivoted link 48 with the eccentric pin 32, and the arms 37 and 44 are connected with such pin by a similar toggle 49-50 and link 51.

The position of the inlet port 52 and the exhaust ort 52 which are formed in the rear casing plate and are similar in the construction and arrangement of the walls of the ports and connected passages to those of the first described form of engine, is shown in full and dotted lines inFigs. 9, 12 and 13. In order to afford the most direct escape for the burned gases and prevent -back pressure in any part of the exhaust spark plug, as shown,.is arranged to ignite the explosive charges of gas at the point where the charges of gas in the working chambers. between the pairs of cooperating pistons D and F, D and E D F .and D and E are compressed to the greatest degree.

The spaces to the rear of the pistons F, F l?" and F are idle during the greater part .of each revolution, but are utilized during the exhaust portion of the cycle to pump charges of air into the working spaces or chambers to scavenge them ofv burned gases. Inorder to permlt the air to breathe back and forth freely except when the pumping action occurs, the ring 45 to which 1s secured the variable speed pis-' tons F and F is formed with two breathing passages, one marked 56, leading from the rear of the piston F radially inward and terminating in a lateral arc-shaped port 56 and the other, marked 57, leading radially from the rear of the piston F and terminating in an arc-shaped ort 57; both of which ports are arrange to register with a series of recesses 58 out in the face of the adjacent portion of the front casing plate 31 and opening inwardly inside the casing. The ports 56? and 57 are of such lengthas to bridge the uncut portions of the casing face (which are left merely as bearing surfaces) and the recesses 58 therefore provide in effect a continuous opening into the spaces between the pairs of pistons F and D and F and D, extending from a point some distance in advance of the end of the exhaust port (where the (pumping action of the pistons is complete as hereinafter explained) to a point-where it' overlaps the beginningof the .exhaust port. From the latter pointto the first mentioned point the face of the casing plate is continuous and the ports 56 and 57* are sealed.

The ring 42 is formed with diametrically opposite similar ports and passages arranged to cooperate with a simllar series of recesses 59 in the rear casing plate 52, the passage and port to the rear of the piston E being marked 60 and 60*. respectively, and the passage and port to the rear of the piston E being marked 61 and 61, respec-' tively. As shown in Figs. 9 and 10, the pistons D, D D and D are each formed with a' recess 62 which is adapted to cooperate with; a pair of bridging channels 63 and 63 formed in the piston chamber wallin the peripheral portion of the front casing plate 31, the purpose of which will be later explained. In Fig. 9 the outline of the channels 63 and 63 is indicated by dotted lines.

The mode of operation of the engine which has just been described is in most respects the same as that of the form first described, the explosive gas being taken in, compressed, burned and exhausted in the working chambers in the same manner. The manner in which the power of-the burning gas is transmitted to the motor shaft may be regarded as the reverse of that exhibited in the first described engine, since the spreadin of the pistons D and F creates a pull on t e toggle members 49 and 50 which thrusts the link 51 against the eccentric pin 32, and as the pistons pass'the dead center position shown in Figs. 9 and 11, moving in a counter position shown-in Figs. 9 and 11, moving in a counter-clockwise direction, this thrust exerts a rotative effect until the tog-V gle stra-ightens to linear position, atwhich time the piston D uncovers the exhaust port. The piston E meanwhile has been accelerating and separating from the piston D, taking in air first through the passage 60 and port 60= and later also through the front end of the exhaust port, the pistons F, D and E then'occupying the'positlons in which the pistons E, D and F, respectively, are

' pistons, which would otherwise take around the piston F. The-position o the shown on Fig. '9. From this position, the

piston F accelerates and the piston E legs,

with the result of causing such pistons to approach the piston D from opposite sides, expelling the burned gas from the space I back of the piston D, and also expelling the tinue closing together the air is expelled into i the space between the pistons F and D, displacing an equal volume of burned gases. The solid uncut portion or bridge 64: of the piston chamber wall between the channels 63 and 63*prevents exhaust gases or air being drawn in between the pistons F and D in the further, separating movement of the lace pistons F, D and E just before the closing of the exhaust corresponds to the position of the pistons F, D and *E" shown-in Fi 11. I

t is obvious that my invention is susceptible of various modifications and variations, other than above described, by changes in the construction and arrangement of the various parts or the substitution of equivalents and without changing its mode of operation or its essential elements. I therefore do not limit my claims to the specific embodiments of my invention herein shown and described. 7

I claim:

1. In an explosion engine, an annular piston chamber, a motor shaft, a piston in said piston chamber rigidly connected with said shaft, a piston in said piston chamber mounted to, rotate coaxially of said motor shaft, a jointed connection between said pistons, an eccentric pin, and a link pivoted to said' eccentric pin and pivotally connected to said jointed connection.

2. In an explosion engine, an annular pis ton'chanrber, a motor shaft, apiston in said piston chamber rigidly connected with said shaft, a piston in "said piston chamber mounted to rotate coaxially of said motor shaft, a toggle having the outer ends of its members.connected one to each piston, an

3. In an explosion engine, an annular piston chamber, a motor shaft, a pair of pistons arranged diametrically opposite in said piston chamber and rigidly connected with. said shaft, a pair of rigidly connected pistons arranged diametrically opposite in said piston chamber and mounted to rotate coaxially of said motor shaft, a ointed connection between one of said first menitioned pair of mounted to rotate pistons and one of said second-mentioned pair of pistons, and a link pivoted to said eccentric pin and pivotally connected to said jointed connect on.

4:. In an explosion engine, an annular piston chamber, a motor shaft, a pair of pistons arranged diametrically opposite in said piston chamber and rigidly connected with said shaft, a pair of rigidly connected pistons arranged diametrically o posite in said piston chamber and mounte to rotate coaxially of said motor shaft, a toggle having the outer ends of its members connected one to one of said first-mentioned pair of pistons and the other to one of said second-mentioned pair of pistons, an eccentric pin, and

a link pivoted to said eccentric in and also pivoted to the knee of the togg e.

5. In an explosion engine, an annular piston chamber, a motor shaft, a piston in said piston chamber rigidly connected with said shaft, 9. piston in said piston chamber 1 shaft, a toggle having the outer ends :of its v of the toggle,

. first-mentions revolution. 85,.

1 tor shaft and the ranged alternately with said first-mentioned motor shaft and outer ends of'its'members connected one to members connected one to eachpiston, an eccentric pin, and a link pivoted to said eccentric pin and also pivoted totheknee said link being arranged to flex said toggle inwardly and outwardly from straight position at each revolution whereby said second-mentioned piston will be caused to ap roach and moods from said "6. In anexplosion en 'ne, an annular piston chamber, a motor s aft, four pistons 1n said piston chamber arranged ninety degrees apart and rigidly connected with said shaft, two pairs of. diametrically opposite pistons in-said chamber, the pistons of each 'pair being rigidly; connected to each other and mounted to rotate coaxially of said'mofour plstons being arfour pistons,

and means for oscillating said two pairs of rotatably mounted pistons to cause the pisto'ns on opposite sidesof any; given one of said first-mentioned pistons to a proach and recede from such particular plston during the same period oftim'e,

7. In aH-OXPlOSlOIl engine, an annular pis-. istons'm 'arranged nmety deton chamber, a motorshaft, four grees apart and rigidly connected with said shaft, two pairs ofdiametricallyop osite pistons in said chamben the pistons 0 each connected toxeach other and mounted to rotate coaxially of said arran edalternately with said first-mew tione four pistons, a toggle having the said first-mentioned four connected pistons and the other to one of, said pairs of onnected pistons, and a second toggle having coaxially of said motor piston twice during suchuice of said first-mentioned toggle,

the four pistons being nected pistons,

to said first-mentioned four connected tons and the other to the other one of said pairs of connected pistons, said toggles be ing similarly connected at an angle of ninety degrees from each other, an eccentric pin,

a link pivoted to said eccentric pin and also pivoted to the knee of said first-mentioned toggle, and a second toggle also pivoted to said eccentric pin and pivoted also to the knee of said second-mentioned toggle.

8, In an explosion engine, an annular piston chamber, a motor shaft, four pistons in said piston chamber arranged ninety degrees apart and rigidly connected with said shaft, two pairs of diametrically 'opposite pair being rigidly connected to each other and mounted to rotate coaxial ly of said motor shaft and the four pistons being arranged alternately with said first-mentioned four pistons, a toggle having the outer ends of 7 its members connected one to said'first-menpistons in said chamber the pistons ofeach tioned four connected pistons and the other to one of .said pairs of connected pistons, and a second toggle having the outer ends of its-members connected mentioned four connected pistons and theother to the other one of said pairs of con' said toggles being similarly one to said firstconnected at an angle of ninety degrees from .each other, an eccentric pin, a link pivoted -end-mentioned toggle,

to said eccentric pin'and also pivoted to the and a second toggle alsoipivot-ed tosaid eccentric pin and pivoted also to the knee of said secsaid links being each arranged wardly and outwardly from straight position at each revolution.

to flex its connected toggle in- 9. An engine according to claim 6 prov a .i

vided with'means for sealing every second space between the pistons, the alternate.

spaces being open to atmospheric pressure. 10. An engine according to claim '6 providedwith means for sealing the s the rear of the four istons rigi ly conaces to nected to the .motor s aft, the spaces in front of such pistons being open to atmos- 4 pheric pressure.

11. An engine according. to-claim 6 and provided with means for sealing every second space between vthe pistons, the alternate spaces being and having'also an inlet port and anexhaust ort in its piston chamber walls arrange open to atmospheric pressure,

to cooperate with the pistons and 1 respectively admit gas into the sealed spaces and exhaust the products of combustion 1 therefrom.

12. Ane ine according to claim 6 and provided wit means for sealing the spaces to the rear of the four pistons rigidly conneoted to the motor shaft, the spaces in front of such pistons, being open to atmospheric pressure, and having also an inlet port and an exhaust port in its piston chamber walls arranged to cooperate with the pistons and respectively admit gas into the spaces to the rear of the four pistons rigidly connected to the motor shaft and exhaust the products of combustion therefrom.

13. An engine according to claim 6 in which the means for oscillating the rotatably mounted pistons include an eccentric pin, a train of linkage connected to said eccentric pin and the four connected pistons and also connected to one of the pairs of diametrically opposite connected pistons, and a second train of linkage also connected to the eccentric pin and the four connected pistons and connected also to the other one of the pairs of diametrically opposite connected pistons.

14. In an explosion engine, an annular piston chamber, a motor shaft, four pistons in-said chamber arranged ninety degrees apart and rigidly connected with said shaft, four pistons in said chamber arranged alternately with said first-mentioned pis tons and mounted to rotate coaxially of said motor shaft, means for oscillating said rotatably mounted pistons to cause the pistons on opposite sides of any given one of said first-mentioned pistons to approach and recede simultaneously from such particular piston, means for sealing every second space between the istons, whereby it may function as a worl zing chamber, the piston chamber walls being formed with intake and exhaust ports opened and. closed by the piston to admit gas into such working chambers and exhaust the burned products of combustion therefrom, and means for sealing the alternate spaces during part of the exhaust period in an adjacent working chamber, the piston chamber walls being formed with a bridging passage arranged to place such alternate spaces when sealed successively in communication with such adjacent working chamber.

15. An explosion engine according to claim 14; in which the bridging passages include two separated channels and the pistons connected to the motor shaft are formed wifh recesses arranged to connect said channe s.

16. An explosion engine according to claim 14 in which the chambers following the pistons secured to the motor shaft are arranged to function as working chambers and the bridging passage is arranged to place each working chamber in communication with the chamber in front of it during the concluding part of'the exhaust period.

17. In an explosion engine of the character described and having an annular piston chamber wall formed continuous with opposed fiat faces extending inwardly from the chamber, a frame secured to the motor shaft and formed with a peripheral flat ring equipped with pistons arranged to travel in said piston chamber, a pair of oscillating frames each formed with a peripheral flat ring equipped with pistons arranged to travel in said piston chamber and arranged within said flat faces of the piston chamber wall one on each side of said first-mentioned ring, the rings on said oscillating frames being formed with passages arranged to place each alternate space between the pistons in communication with the atmosphere.

18. In an explosion engine of the character described and having an annular piston chamber wall formed continuous with opposed flat faces extending inwardly from the chamber, a frame secured to the motor shaft formed with a peripheral flat ring equipped with pistons arranged to travel in said piston chamber, a pair of oscillating frames each formed with a peripheral flat ring equipped with. pistons arranged to travel in said piston chamber and arranged within said flat faces of the piston cl :nher wall one on each side of said first-wv ring, the faces of the piston. chanmer walls being formed with recesses and the said oscillating frames being form cooperating ports and passes (inn place each alternate space m. ween tons in communication with the aru during part of a revolution of the i all and seal it during the remainder of an:

revolution.

CARL O. FARNEE'AN. 

